Alloy



Patented Mar. 29, 1932 UNiT-ED STATES PATENT OFFICE CHARLES WILLIAM THOMAS, OE REID!0RD, AND VINCE NT. WEAVER ALLEN, OF DETROIT, MICHIGAN, ASSIGNORS 'IO REVERE COPPER AND BRASS INCORPORATED,

OF ROME, NEW YORK, A CORPORATION OF MARYLAND ALLOY No Drawing.

This invention relates to alloys and certain products made therefrom. The invention relates more particularly to alloys of the socalled brass type and certain articles of manufacture made therefrom.

Brass is one of the best known alloys and has been put to a great variety of uses. It consists of copper and zinc compounded in various proportions. A common brass is the so-called Muntz metal consisting of about 60% copper and 40% zinc.

Conditions arising in the use of brass products make it highly desirable to obtain an alloy capable of being worked up into a final product having a fine grained smooth finish on which a bright polish may be produced. In the working up of many brass products where drawing operations are employed, it is frequently found that those portions of the fabricated article where the draw has been most severe, present a so-called orange peel surface. A surface of this kind is ill adapted to take on a smooth polished surface, as is um plated and the like.

desired on that sort of article to be chromi- The brasses' heretofore on the market are therefore not com-, pletely satisfactory in this respect.

As a result of our investigations, we have determined that the, common brass alloys may be materiallyimproved in this respect by the addition thereto of at least one more alloying constituent, so that products made therefrom ma have a smooth finish which is adapted to ta e on a high polish. Platingsof various kinds, such as chromium, nickel and the like may be easily applied while providing an exceedingly smooth finish.

The present inventlon contemplates the addition of aluminum inamount not to exceed. about 1.0% to the copper and zinc going into the brass. -Inthe present preferred practice of the invention the amount of aluminum added does not exceed about 0.5%. Desirable effects are obtained when using as little as 0.1% aluminum, but in the present practice of theinvention, we are employing approximately 0.25% aluminum.

The proportions'of copper and zinc employ in the alloy vary accordin to the use to which the final product is to e put. In

Application filed September 26, 1930. Serial No. 484,705.

the case of Muntz metal, we employ the stated amount of aluminum, and the remainder of the alloy constitutes a combination of'approximately copper and 40% zinc. The amount of zinc, or the amount of copper, or both, may be suitably reducedto offset the particular amount of aluminum employed in order to determine the relative proportions ofmetals going into the alloy.

v In accordance with the invention, aluminum in amount not exceeding about 1.0% in combination with copper 50 to and zinc 5.0 to 49% is employed. While improved recopper.

An alloy compounded in accordance with the present invention possesses peculliar advantagesin the following respects, although it is to be understood that We are not to be restricted to the explanation that at the present time appears tenable to us:

A small quantity of aluminum used as specified inthe alloy of copper and zinc appears to produce a material possessing a greater plasticity than is possessed by corresponding alloys without the addition of aluminum. It has been observed that in annealing a base alloy containing the stipulated limits of aluminum it is not necessary to exercise the same control of temperature or time of anneal as is the case when the aluminum is not present.

It seems probable that the advantages gained b the use of aluminum in brass aloys are ue primarily to the greater plasticity of the alloy either above or below the recrystallization temperature. The combination of these effects renders it possible to In the range of alpha brass the addition of the indicated percentages of aluminum yields an ultimate product that is more ductile and soft than the corresponding alloys without the aluminum, and without substantial loss of tensile strength. in the range of alloys containing normal mixtures of alpha and betajbrass, as typified by Muntz metal, the addition of aluminum appears to cause the beta-phase, or a modification the beta phase, to absorb the alpha phase; and it is possible to obtain specimens f the Muntz metal type with. the addition of aluminum that appear to have a single phase at room temperature. This phase probably represents a solid solution of copper, aluminum and zinc and it not to be confused with retained beta obtained by quenching. it is possible that the benefits observed. to accrue from the use of aluminum as indicated are largely due to the ties oi t is new phase which takes the place e alpha beta mixtures ordinarily observes in alloys containing less than 64% copper t will therefore be apparent that the practice of the present inv ion makes possible the production of so-c d brass alloys that are highly useful in the manufacture of various metal products. This is particularly true when the alloys of the inventien employed to produce mecha;iically-worlzed articles of manufacture,

We claim:

1. An alloy consistine; 95%, zinc 5 to 29%, and. 0.257.

2. An alloy consisti zinc 5 to 49%, and ale 3. An alloy COHSlStlR. zinc 3-6 to 49%, and alu 4, An alloy consist zinc 36 to 49%, and a;

In testimony where" tures.

CHARLES WEL VINCENT WE i cooper 50 to mum 6.1 to 

